I have bought an apartment in Florida very near my son and his family.
My granddaughters made me do it, although they don't know it. Not having had a grandparent as I grew up, I had no idea what grandparenting - or should I say grandchilding? - involved, but living in the intensely familial atmosphere of Israel for 22 years has demonstrated its many benefits at one remove. These little girls are now 5 and 9, and the years seem to be accelerating. As they mature, I want to know them as people and be involved in some of their day-to-day events. I have no medical reason to expect my life to end soon, but it will end someday, and it would be nice to be able to say "Goodbye" to my children in person, not to mention the advantage of having their advocacy in the face of institutions that - everywhere in the developed world - are mostly geared to curing. To paraphrase Leonard Cohen, "There ain't no cure for [mortality] love."
If I could afford it, I would also buy an apartment near my daughter, but she happens to live in the Pacific Northwest, where real estate was almost unaffected by the recent bursting bubble, so financial considerations prevent that. Being on the same continent as she should make it easier for us to spend more time together.
As it is, I will still be in Israel for part of the year, so there remains the problem of summer heat in both Tel Aviv and Florida. Air-conditioning is not a solution for someone whose preference is walking to do daily life errands: grocery shopping, post office, bank, walking the dog, etc. Anyone need a responsible house-sitter in a place that's nice and cool in August?